Of the psychosocial risk factors, positive and negative aspects of relationships are two of the most reliable predictors of cardiovascular morbidity and mortality. However, most prior work has examined positive and negative aspects of relationships in isolation. Such a practice ignores the possibility that these dimensions can co-occur (i.e., ambivalence) in specific ties. Our prior work has shown that ambivalent ties are common (close to 50% of important network ties) and stable over time. More important is the fact that perceptions of relationship ambivalence are related to increased cardiovascular risk, including greater ambulatory blood pressure, cardiovascular reactivity, inflammation, and coronary artery calcification. This proposal will thus pursue three major aims to tackle the issue of why such links occur based on the social ambivalence and disease (SAD) model. Aim 1 will test the antecedent factors that influence the development of ambivalent ties and link them to health (i.e., harsh early family environment, concurrent positive and negative relationship interactions). Aim 2 will examine the factors that influence the maintenance of ambivalent ties (i.e., commitment, indirect coping strategies, implicit relationship representations) and if they moderate links to health. Finally, aim 3 will seek to directly model the mechanisms linking these ambivalence factors to cardiovascular risk as specified by the SAD model. In order to pursue these major aims, 3 integrative studies will be conducted. These studies utilize different protocols and health-relevant cardiovascular assessments which capitalize on our prior work. Study 1 will test if the early family environment is linked to relationship ambivalence and cardiovascular health. Study 2 will track the development of ambivalence in early dating relationships and corresponding links to cardiovascular function. Study 3 will examine if relationship commitment, indirect coping strategies, and implicit relationship representations moderate the links between ambivalent ties and health in longer-term married couples. Finally, each of these studies will directly model relevant mechanisms based on a novel theoretical framework (i.e., SAD model). Importantly, these studies represent critical theoretical steps in linking relationships to health and our prior studies provide evidence for the feasibility and potential of the proposed work.